We used to think humans were the only animals to use tools, until researchers began spending time with wild chimps. Some groups use wooden hammers to break up nuts, others use rocks. Lots of chimps use sticks to fish for termites, but their techniques vary, even between neighbouring groups. Different behaviour in different regions gave scientists a real insight: it's possible that young chimps learn how to make and use tools by imitating the actions of experienced adults. If that's true then they learn in the same way human children do - and just as in humans this creates local customs which are passed down the generations. Now that we know this, we are seeing patterns of behaviour in other areas of chimp lives - from courtship to grooming behaviour - can vary from one group to another. A chimp from West Africa would find the ways of East African chimps quite foreign.